To record such information as characters, images or identification marks, etc. on a fabric, so-called textile printing by use of a dye or pigment has been practiced for keeping good washing resistance, wear resistance, etc. However, textile printing requires a printing plate for each pattern and is very poor in flexibility to entertain changes of images. When information-bearing fabrics of various kinds are produced in respectively small quantities, for example, when serial numbers changing each time of recording are printed, it can be generally said that such textile printing cannot be used at all.
Considering the above flexibility, various printers used for OA apparatuses are very promising. These printers include heat transfer printers, impact printers, electrophotographic printers, ink jet printers, sublimation type heat sensitive transfer printers, etc. Among them, the former three printers use mainly pigments as coloring agents. However, in the combination of a pigment and a fabric, even though an image can be formed temporarily by a pigment on a fabric, washing, friction, etc. easily deprive the fabric of the pigment, and so these printers cannot be said to be suitable for fabrics. On the other hand, the latter two printers are described below in detail.
For the ink jet printer, a method of printing an ink containing a dye and heating it for dyeing has begun to be studied for application of the printer to fabrics. However, since the ink is liquid, printing on a fabric not treated at all causes blurring, thereby not allowing a clear image to be obtained. So, before printing, the fabric must be treated to prevent blurring thereby raising the cost disadvantageously. Even if the additional cost of treating the fabric for preventing blurring is disregarded, all the dye applied is not fast deposited on the fabric, and some of the dye remains loose to pose a serious problem in view of fastness to friction, recontamination, etc.
On the other hand, in the case of sublimation type heat sensitive transfer printer, a sublimable dye is used, and the treatment of the fabric for preventing blurring is not required unlike the ink jet printer. So, the printer seems to be preferable. However, the sublimation type heat sensitive transfer printer uses a very highly sublimable dye to keep the heating temperature lower, since the thermal head used in the printer becomes shorter in life if the heating temperature is higher. If such a very highly sublimable dye is used for dyeing the fabric, it is low in fastness to washing, ironing, etc., and the conventional sublimation type heat sensitive transfer printer cannot be immediately applied to fabrics. The sublimation type heat transfer technique can be used for printing fabrics if the dye used is good in fastness, but such a dye good in fastness cannot be used in view of the life of the thermal head since it is high in sublimation temperature.
As described above, any of conventional printing techniques cannot provide images excellent in washing resistance and wear resistance, with flexibility to changes of images at low running cost.
In addition to the above problems, the printers other than the ink jet printer require the recording medium to be smooth on the surface, and so the problem must overcome that ordinary fabrics are very poor in surface smoothness compared to paper, etc.